If Stomp client crashes (or disconnects unexpectedly) when there are unconsumed messages in the broker, the subscriptions are not removed from the broker and some phantom consumer is still consuming messages. If you connect other client, it receives only half messages (other half messages goes to that phantom consumer still left afrter client disconnect). There are no error logs in activemq logs. We are using stomp client, whith client acknowledge mode, so on broker restart, all messages are delivered properly. You can also see in jmx console, that subscription still exists whithout any connection left.